Energy is converted and transported in hydraulic systems, and losses occur in this conversion of energy and transport of energy. As such, mechanical and hydraulic energy is thereby converted into heat. The object of a cooling device is to dissipate this heat from the hydraulic system. The fan of a cooling device can typically be driven hydraulically. The hydraulic drive unit for an allocated hydraulic motor may be designed as a separate circuit, which is independent of the circuit of the fluid that is to be cooled.
A valve of the above mentioned type is known from the subsequently published DE 10 2012 008 480.3. The known valve is used to actuate a hydraulic drive of a fan as a function of the temperature of the fluid that is to be cooled, or more precisely, to predetermine the speed of the fan. The valve and the fan drive, which is actuated by the valve, are disposed in a joint hydraulic circuit. Room for improvement still exists in the use of the known valve in sluggish hydraulic systems having more limited adjustment dynamics. In addition, limiting the control pressure predetermined by the valve is desirable to be able to protect the thermal element against overloads.